Electrical and Reliability Characteristics of FinFETs With High-k Gate Stack and Plasma Treatments

• Published in: IEEE transactions on electron devices 2021-01, Vol.68 (1), p.4-9
• Main Authors: Li, Yan-Lin, Chang-Liao, Kuei-Shu, Li, Chen-Chien, Huang, Chin-Hsiu, Tsai, Shang-Fu, Li, Cheng-Yuan, Hong, Zi-Qin, Fang, Hsin-Kai
• Format: Article
• Language: English
• Subjects: Current leakage; Dielectrics; FinFETs; gate stack; Hafnium oxide; high-<italic xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">k (HK) dielectric; Leakage current; Leakage currents; Logic gates; metal gate; Plasma; plasma treatment; Plasmas; Reliability; Stress; Titanium dioxide; Zirconium dioxide
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2020.3038364

Effects of high- {k} gate stacks and plasma treatments on electrical and reliability characteristics of FinFET were comprehensively studied in this work. A higher ON-current, higher ON-/OFF-current ratio, smaller subthreshold swing (S.S.), lower gate leakage current, and better reliability characteristics in FinFETs are simultaneously achieved by a HfO 2 /ZrO 2 /HfO 2 gate stack. The improvement can be attributed to its higher {k} -value, fewer oxide traps, and oxygen vacancy in gate stack. A higher ON-current of FinFET can be obtained with an F-based plasma treatment, which, however, also induces a larger gate leakage current. A plasma treatment with F- and N-based ambient on gate stack is shown to obtain a higher ON-current and acceptable gate leakage in FinFET. Furthermore, a larger ON-current, higher ON-/ OFF-current ratio, and a smaller S.S. in FinFET can be achieved with a TiO 2 stacked gate dielectric.